Big-city coffee shops have recently begun cracking down on "laptop hobos," covering up power outlets to stop people from spending hours at a table while spending $3 on coffee. The trend has generated the mostbuzz in New York City, but it has spread to some coffee shops in other cities, too, namely San Francisco.

The idea is that laptop hobos drive away other potential customers by hogging tables — and without any specific obligation to spend money themselves. Rather than confronting them directly, the outlet-blocking strategy relies on the eventual depletion of batteries to drive lingerers away. But since this can alienate some customers, most coffee shops still resist the urge to withhold their electricity.

Thanks to emerging power-outlet technology, though, this may soon be a moot point. As the Verge reports, Sony is developing an outlet that can "determine a user's identity or permissions," raising the prospect of pay-as-you-go electricity in public places (along with other potential uses, such as managing energy consumption in large buildings or preventing theft of electronic devices).

Pay outlets have existed for years, like the Smarte Carte kiosks found at many airports. But the new technology would be more sophisticated, capable of identifying an individual user — via a card, smartphone or other device that employs near-field communication — and then determining his or her permissions for a particular plug. These outlets have integrated circuit (IC) chips built into them, and send users' authentication information along the power line itself, according to the Verge.

On top of potentially changing the relationship between baristas and laptop hobos, this could also be a boost for another industry: electric vehicles. Ever since Thomas Edison's heyday, the rise of electric cars has been stymied by the difficulty of building broad networks of recharging stations. While companies like Better Place are now working to establish such networks, they would likely be easier to operate if power outlets could recognize and charge each customer electronically.

The idea of such intrusive outlets doesn't sit well with everyone, though. It has raised fears of privacy invasion and identity theft, not to mention the natural indignation at paying for something that used to be free (especially if you're also being charged for WiFi). But with coffee shops increasingly covering up power outlets, electricity was already ceasing to be free in many cases. Smart outlets seem to offer a compromise, and may even help erode the myth that electricity is ever truly "free."

Plus, as one commenter notes on the Verge, eventually "we might even get free coffee at some charging stations."

For more potential uses of authentication outlets, see Sony's promotional video below:

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